Gaseous State

Boyle's Law Charles' LAw Avogadro's Law Ideal Gas Law


If the thermal energy is greater than the forces of attraction, then we have matter in its Gaseous state. Molecules in the gaseous state move with very large speeds and the forces of attraction amongst them are not sufficient to bind the molecules at one place, with the result that the molecules move practically independent of one another because of this feature, gases are characterized by marked sensitivity of volume change with change of Temperature & Pressure. There exists no boundary surface and, therefore, gas tends to fill completely any available space, i.e., they do not possess a fixed volume.

A Gas is said to be Ideal if it follows Following Laws : -

  • Boyle's law
  • Charles law
  • Avogadro's law
  • Daltons law


Boyle's Law

The equation which gives the simultaneous effect of pressure and temperature on the volume of a gas is known as an ideal gas equation or an equation of state for an ideal gas.

It can be derived by combining Boyle’s law, Charles’ law and Avogadro’s hypothesis as shown below:


n = number of moles
R = universal gas constant = 8.3145 J/mol K
N = number of molecules
k = Boltzmann constant = 1.38066 x 10-23 J/K = 8.617385 x 10-5 eV/K
k = R/NA
NA = Avogadro's number = 6.0221 x 1023 /mol

Implications of Ideal Gas Law


Clicky Web Analytics